1. Field of the Invention
The present invention relates to a buffer material used for packing a wafer carrier at the time of shipping of the wafer carrier in which a semiconductor wafer or the like is stored.
2. Description of the Related Art
In the prior art, there has been disclosed a packing body comprising a plurality of buffer bodies that sandwich contents therebetween and are accommodated in a packing box and a reinforcing body that reinforces at least one of these buffer bodies (for example, refer to Patent Document 1). The contents are a substrate carrier in which an opening portion of a carrier main body that contains a wafer is opened/closed by a lid body, and a retainer that holds a peripheral edge portion of the wafer is disposed to the lid body. Specifically, the substrate carrier has a carrier main body that accommodates a plurality of wafers in line, a detachable lid body that opens or closes an opened front side of this carrier main body, and a pair of left and right locking mechanisms that are attached to this lid body side by side and fit the lid body to this carrier main body or releases this fitted state. The pair of left and right locking mechanisms are configured in such a manner that locking claws protruding from a peripheral edge portion of the lid body are fitted into and locked with respect to a plurality of locking holes on a front inner periphery of the carrier main body based on an operation of a rotary plate at the time of fitting the lid body to the carrier main body and the locking claws fitted in the respective locking holes of the carrier main body are removed from the respective locking holes and returned to their original positions based on an operation of the rotary plate at the time of releasing the fitted state of the lid body with respect to the carrier main body.
The carrier main body is formed into a front open box type by using a resin. A robotic flange having a rectangular plane is detachably disposed at a central part of a ceiling of this carrier main body, and this robotic flange is held by an automatic carrying mechanism which is called “OHT (overhead hoist transfer)”, thereby carrying the substrate carrier. Further, a pair of left and right rear retainers that hold a rear peripheral edge of each accommodated wafer are aligned and provided in the vertical direction on a rear wall inner surface of the carrier main body. Furthermore, the lid body is constituted by combining a resin housing and a plate. A deformable endless gasket is fitted to the peripheral edge portion of this lid body, and a large front retainer that elastically holds a front peripheral edge of each wafer accommodated in the carrier main body is attached to the central part on the rear side of the lid body in a vertically long manner. It is to be noted that the substrate carrier is put into a packing bag made of polyethylene, packed, and accommodated in a packing box with the opening portion of the carrier main body facing the upper side when wafers are not stored in the carrier main body, or the substrate carrier is put into the packing bag made of polyethylene, packed, then put into a packing bag made of aluminum as required, double-packed, and accommodated in the packing box with the opening portion of the carrier main body facing the upper side when the wafers are accommodated in the carrier main body.
On the other hand, the buffer body is a buffer material that can be fitted in contents. A peripheral wall of the buffer material is formed of an inner wall formed on a peripheral edge portion of the buffer material, a bulge portion that is formed on the inner wall and bulges outward, and an outer wall that is formed on this bulge portion and faces the inner wall of the buffer material to interpose a gap therebetween. Moreover, a peripheral edge portion of the reinforcing body is formed into a curved shape so that the peripheral edge portion of the reinforcing body can be engaged with an outer wall end portion of the buffer material. Additionally, a plurality of concave portions are formed on the peripheral wall of the buffer material in the circumferential direction at intervals, and the bulge portion of the buffer material is bent and formed into a bellows.
In the thus configured packing body packs, since contents are packed in the packing box through at least the buffer bodies and the reinforcing body, external force or impact shock acting on the packing body can be effectively absorbed, corner portions, ridge line portions, or the like of the packing bodies can be prevented from being easily damaged due to collision or fall, and possibilities that a peripheral area is contaminated, that a storage space expands, and that reuse or recycle is obstructed can be suppressed. Further, since the contents correspond to the substrate carrier in which the opening portion of the carrier main body that accommodates wafers is opened or closed by using the lid body, even in case of packing the substrate carrier with the retainers, impact shock at the time of collision or fall can be appropriately absorbed, and possibilities that the corner portions or ridge line portions of the packing body are easily damaged can be effectively eliminated. Furthermore, since the peripheral edge portion of the reinforcing body is bent and engaged with the outer wall end portion of the buffer material, the peripheral wall of the buffer material can be prevented from falling inward or outward or from being deformed, thus sufficiently protecting the contents. Moreover, since the plurality of concave portions are formed on the peripheral wall of the buffer material in the circumferential direction at intervals, strength or rigidity of the buffer bodies can be enhanced. Additionally, since the bulge portion of the peripheral wall of the buffer material is bent and formed into a soft bellows, expansion and contraction or bending of this bellows can alleviate the impact shock acting on the contents, and hence acceleration generated at the time of falling can be reduced.